A buffer strip shall be provided along the entire perimeter of the property of which multifamily dwelling units or mobile homes are erected, of at least 50 feet in width measured inward from the property line and retained in natural woods, or suitable landscaped with grass and/or ground cover, shrubs and trees. No parking or roadways, except roadways crossing at right angles to the buffer area for the purpose of providing access to the property, shall be allowed in this area. The buffer strip area shall not be considered as part of the usable open space or recreation area as required by Chapter 326, Mobile Homes and Mobile Home Parks, as amended.